WASHINGTON — Donald Trump’s unorthodox bid to win the Republican presidential nomination has some distinctly traditional trappings: offices and employees across the country.

Trump, the winner in two of the first three states in the presidential primary season, has long been laying the groundwork for more victories in March, when two dozen states go to the polls, new campaign finance reports show.

In January, his campaign had roughly 100 people on its payroll and a scattershot of field consultants and offices from Alabama to Texas, giving him a head start on connecting with voters as the primary calendar intensifies.

Trump’s efforts are disclosed in his campaign finance report filed Saturday with the Federal Election Commission. The records provided by all the campaigns covered fund-raising and spending in January, and do not capture any activities in the first three weeks of this month.

The billionaire has vowed to spend ‘‘whatever it takes’’ to lock up the GOP nomination. He has so far invested about $17.5 million into his bid, a fraction of what most of the other candidates are spending.

But Trump has been able to pump money into employees and offices in part because he saves cash in important ways: He doesn’t do traditional fund-raising, which can be pricey, and has done far less advertising than is typical for a leading presidential candidate.

The robustness of Trump’s field operation as outlined in the January fund-raising reports looks more like that of Democrats Bernie Sanders and Hillary Clinton than any of his four Republican competitors.

At the beginning of the year, Trump had more salaried campaign employees than Texas Senator Ted Cruz or Florida Senator Marco Rubio, his two closest competitors. In addition, Trump had at least 17 paid field consultants in states beyond the first four to vote, a network that touched Alabama, North Carolina, Ohio, and Virginia.

And his campaign was already paying for office space in eight states that vote in March. Sanders and Clinton each had a presence in at least a dozen states voting in March, their January campaign finance reports showed.

Other Republicans — focused on notching a win in one of the four February voting states — didn’t appear to be thinking much about March back in January, that month’s financial reports show.

Ohio Governor John Kasich had two offices in March-voting states (including one in his home state), Rubio one and Cruz none, though his campaign headquarters is in Houston, where voters weigh in March 1.

Rubio’s campaign said it will open a Georgia office on Monday, and earlier set up offices in Birmingham, Ala., and Maple Grove, Minn.

Rubio’s campaign, which appeared to have no March-state field staff in January, is now redeploying people from Iowa and New Hampshire. Among the recent hires is Chip Englander, who had been Rand Paul’s campaign manager. Based in Ohio, he’ll oversee Rubio’s efforts in the Midwest.

Cruz’s campaign showed payments to a handful of strategists in March-voting states, including Michigan.

The campaign finance reports show Kasich and Rubio had little cash to work with in January: They started the month with $1.5 million and $5 million, respectively. Cruz had $13.6 million at the beginning of February.